﻿namespace 九
{
    internal class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World!");
        }
    }
    interface A
    {
        public double area();
    }
    interface B
    {
        public void setColor(string c);
    }
    interface C : A, B
    {
        void volume();
    }
    class Cylinder:C
    {
        double radius, height;
        string color;
        public double area()
        {
            return radius * radius * 3.14 + height * (radius * 2 * radius);
        }
        public void setColor(string c)
        {
            color = c;
        }
        public void volume()
        {
            Console.WriteLine(radius * radius * 3.14 * height);
        }
    }
}
